B1 Special Operations
The kit includes all the parts down to the last piece of wire to build a B1SO in the gain stage configuration.
- PCB
- All passive parts including a genuine Alps 'Blue Velvet' volume control
- All active parts / semiconductors
- A gorgeous chassis
- All hardware and wiring
- Power Supply
Note - The AC Power supply (a.k.a. the wall wart) included with the kits is suitable for mains voltages from 110 to 125VAC and has a NEMA 1-15P plug (a.k.a. a US two prong plug). Builders with mains voltages ranging from 220 to 240VAC will need a step down transformer. Both plug adapters and step down transformers are commonly available in travel kits. 15VAC Power supplies are also readily available world-wide. If you need a recommendation, we'll be happy to help.
The B1 Special Operations, B1SO, is a small, yet advanced and flexible, audio line level pre-amp. It packs a lot of performance into a small package. At a svelte 20cm x 13cm x 5cm, it is ideal for a desktop or dorm, but it's perfectly at home in the 'big rack' as the heart of a high-fidelity audio system.
It can be built in three configurations:
1) Gain Stage - The most popular option. The kits include all the parts for the gain stage. The gain stage is user-adjustable in 4 steps: 6dB, 12dB, 15.6dB, and 18dB.
2) Buffer - A great option for people that don't need gain in their pre-amp and simply want a source selector and volume control. The buffer is based upon the legendary B1 R2. Builders will need to purchase additional parts not included with their kits to complete the buffer.
3) Gain Stage + Buffer - If your source has a relatively high output impedance and/or you just like the idea of having a buffer in front of your gain stage, this is the option for you. Builders will need to purchase additional parts not included with their kits to complete the buffer.
The B1SO is the creation of Steve Gray / Gray Matter Audio and is the first in a lineup of high-performance products that you can hold in your hand. Steve has been building audio electronics and speakers since high school and translated that passion into an engineering career creating products for Otrona, Sony, Intellimed, Cirrus Logic, Peavey and others. Over the years, Steve developed his passion for all things audio by designing and building gear for himself, his family and his friends and has developed a devoted local following. His gear looks great, sounds great and tests great. We're happy to offer this easy-to-build kit to DIYers world-wide.
The project is suitable for DIYers of all levels. We have a complete build guide detailing every step, and diyAudio forum members including Steve will be there to help if you have any questions in the B1SO Discussion Thread on DIYAudio.